Valve



Patented sept. 15,193.1P

UNITD STATES PATENT -orrier; f

. SAM D. IiERoN, *or DAYTQN, omo

l VALVE Application .mea April as,

' This invention relates to valves and particularly to the poppettype ofvalve which is-used in internal combustion engines.

One object of the invention is the provision of a valve having a hollow valve stem which contains two Aseparate sealed chambers, one at the headfend containing a quantity of cooling medium and the otherl being effective to substantially reduceheat transferenceY from a middle portion of the valve to the stem' tip. l y

Another object of the invention is the provision of a valve of the character mentioned which is formed by swaging the stem end '15 together to concentrically restrict it, the in` termediate portion ofthe valve stem having. a restriction which partitions the space -within the valve stem `into two separate chambers, both of substantial size, the chamber at the head end of the valve containing a quantiy ty of cooling medium which .is liquid at the normal ope-rating temperature o f the valve jto provide for efficientheat transfer by turbulent action of the liquid.

Further objects and advantages of the invention will he Indre fully set forth inthe following description and in the accompanying drawings, in which- Fig. 1 is a' longitudinal section of-a valve at one point in the course of manufacture;

v Figi. 2- is a longitudinal section ofV a valve and guide embodying the present invention; and 1' Fig. is a sectional view of a slightly modied' form of construction.

"In themanufacture of poplet valves used in internal combustion engines 'Tuch valves .are frequently constructed so as to contain a quantity of cooling medium which is liquid 40 at the normal operating temperature of`theA valve, and which acts 'to'v transfer heat from the valve head to the valve stem portions re.-

mote from the head by turbulent action of the medium. The space within the valve stem i is only partlyv filled with this'cooling medium', which may be metallic sodium, or a mixture of salts of potassium'nitratel and lithium nitrate or of other salts of the alkali metals having a melting temperature `welll` below the normal operating temperature of' 1929. serial N, 35,3o3.

the valve. 'Such a valve construction is'par- Q ticularly desirable and effective 1n the eX-f haust valves which often operate at quite vhigh temperatures, particularly exhaust valves of high-speed engines where lightness4 is anfirnportivint` factor. 3 In .accordance wlth the present invention the valve steml contamstwo separate chambers, one containing a quantity of cooling medium and located adjacent the head end of the valve, the other chamber being empty 11 and a stem-12, thev stem having a restriction or partition 13 between the head and the stem end. This partition 13 separates the' space within the valvestem intothe vchambers 14 and 15 both of which .areof substantial size, as shown. The chamber 14, which preferably extends into the head of the valve, is partly filled with a quantity of suitable cooling medium, sodium for eX- ample, or an eutectie mixture ofpotassium and sodium nitrates having a Vmelting temperature well .below the normal operating temperature of the portions of the valve withwhieh the medium is in Contact. Preferablyv av considerable quantityof such meydium is used, but not enough to fill the space,

so that the medium will bein a violent state.

of turbulence when the valve is operating,

' and effectively transfer heat from the valve vhead to the portions of the stem more remote It has been found in accordance with this dium chamber does not extend completely.

to the valve. tip, but terminatesat a point about midway vof the valve so that atthehead end of the valve stem there will be an effective transfer of heat from the head while the stem end of the valve does not reach' Such.

high temperatures as the -portions closer to the head. 'W'ith such' a construction the valvey guide will extend towards the stem end of the valve past lthe cooling medium lool chamber so that the portion of the valve stem which is in contact with the stem tip side of the valve guide is not as hot as the portion of the stem which engages the valve head end of the guide. The valve head end of the guide will thus effectively carry away the heat of the comparatively hot head end of the valve st em while the portions of the guidevin contact with the stem tip portionv the valve is considerably reduced at this portion` and as the chamber .at the valve tip end is filled with air which transfers heat at a comparatively slow rate. The valve springs adjacent the valve tip thus operate at a lower temperature and their effective life is thus increased, as the portion of the valve stem Which'th'ey surround 1s not excesslvely In the formof construction shown in Fig. 2 the valve may be made b v first making ay 'metal valve part as shown in Fig. 1. comprising the head 11 and the stem portion 12 which is constructedwith the enlargements 16 and 17, there being a cylindrical bore 18 extending through the lstem almost completely up to the valve head. This part may then be swag'ed into the form shown in Fig. 2, the enlargements 16 and 17 being swaged concentrieally inwardly to produce the portion 2() of partit-ion 13 and portion 21 ad- 'jacent the valve tip. This leaves the outside surface of the valve stem substantially cvlindrical. The restricted openings 24'and 25 may then be drilled if necessary, and reamed preferably with a slight taper` and the outer surface of the valve stem is finished, a suitable groove being providedat the stem tip portion thereof to receive the hollow collar customarily employed. The cooling medium 26 is then inserted into the chamber 14 through the open restricted stem end. This medium may be inserted as a powder, or as a liquid or a plastic solid. W'hen inserted as a powder the valve niav'be heated to reduce the powder to a liquid state. so that when the4 valve again cools theliouid will freeze in the, head end of the valve 14 which of course is held downwardly1 for this purpose. holds the cooling medium in the chamber 14 while the chamber is being sealed. but of course it is unnecessarv to carry out thisI step if vthe head end of the valve is held down during the sealing operations which will now` Thisthrough the open stem tip, this pin or plug v having been machined and ground to a proper lseat fitting the restricted opening 24 so that empty will not cause the transfer of heat l to the portion of the valve stem near the tip, but the space within the stem tip end will give the advantage of lightness while providing for sufficient heat transfer which, combined with the more effective heat transfer at the head end of the stem will maintain the valve head comparatively cool vand prevent burning or breaking of the valve. After the pin or plug 27 is in place, a stem tip 29 of hard steel is preferably welded at 30 on the end of the stem, holding the pin permanently in place, and providing a hard surface which may receive the impact and pounding due to the operation of the valve without wear or damage. The main portion of the valve may be made of iron or steel of a suitable composition so that the swaging operation may be conveniently effected, and so that the head end of the valve may resist the heat to which it is subjected. If the valve stem is constructedof hard steel a separate steel tip need not be applied, as it has been found that the pin or plug 27 will maintain the seal ofthe cooling medium chamber, under normal operating conditions, merely by its driven connection in the tapered seat.

In Fig. 3 there is shown a slightly modified form of construction, a restriction in this valve being provided as indicated at 32 so as to separate the chamber 33 at the head end of the valve from the empty chamber 34 at the stem end of the valve. ber 33 contains the cooling medium 36 which partly fills this chamber and operates preferably by turbulent action in the manner previously referred to. The valve is prefer` ably made by forming a part having an outward enlargement at the tip which may be swaged concentrically inwardly to provide the tip restriction 37. Before this swaging takes place however a metal cylinder, somewhat in the form of a small metal bag 38 is inserted throughv the open stem end of the valve', the cooling medium in the proper amount having been first added to the valve stem. After the bag 38, which may be of steel or other metal having the desired properties, is inserted in the stem end of the valve, the enlargement on the stem end of the valve part is swaged concentrically inwardly which reduces or constricts the open outer end of the bag 38, and seals this end. Whenthe swaging operation is completed the entire steel tip 39 may be welded or otherwise fixed on the valve end, this welding of course permanently sealing any cracks or minute passages which might be present, and through which the cooling mixture might pass.

While the valvesherein, described, con-v stitute preferred embodiments of the invention, it is to be understood that the invention is not limited to the precise forms, and that changes may be made therein without departing from the scope of the invention which is defined in the vappended claims.

What is claimed is:

1. A valve for internal combustion engines having a closed lchamber in the head end of the valve stem containing a quantity of cooling medium` the valve having a sealed empty chamber of substantial size at the stem end thereof which effectively reduces heatv transference from a middle portion of the valve stem to the stem tip.

2. A valve for internal combustion engines having a longitudinally extending closed space in the stem portion extending to a point near the stem tip, a partition in said space spaced from the stem tip dividing said space into two sealed chambers both of substantial si'ze, and a uantity of cooling medium partly filling t e chamber at the head end of the valve.

3. A valve for internal combustion engines having a longitudinally extending closed space in the stem portion extending to a vpoint near the stem'tip, means insertable through the stem tip partitioning the head end of the space from' the stem tip end thereof to divid'el said space into two separate sealed chambers of about the same length, and a quantity of cooling medium which is a liquid at the normal operating temperature of the valve partly filling the chamber at the head end of the valve.

4. A valve for internal combustion engines having a longitudinally extending closed space at the stem portion extending to a point near the stem tip, means inserted through the stem tip for partitioning the head end of the space from the stem tip .end thereof to form ahead end chamber anda separate sealed stem tip chamber both of substantial length, a quantity of cooling medlum tion engines having a closed chamber in the head end of the valve stem containing a quantity of cooling medium, the valve having a hollow empty sealed chamber of substantial size at the stem end thereof which effectively reduces heat transference from a middle portion of the valve stem to the stem tip, and a valve guide for said valve extending toward the stem end to a location opposite the hollow 'empty chamber.

6. A valve for internal combustion engines having a longitudinally extending closed space at the stem portion -extending to a point near the stem tip, a hollow metal bag in the stein end portion of said space partitioning-the valve head end of the space from he stein tip end thereof to form a head end chamber and a separate sealed stern tip chamber both of substantial lengths reducing heat transference from a middle portion of the stem to the stem tip, and a quantity of cooling medium partly filling thehead end chamber.

7. A valve for internal combustion engines having a longitudinally extending space within the stem portion extending to a point near the stern tip, the Walls of the valve stem' being thickened at a middle portion and at the stem tip end thereof, and

plug means in the thickened portions of the stemwall tightly closingl the thickened portions of the wall and providing a head end chamber and a separate sealed stem tip chamber both of substantial length reducing the heat transference from a middle portion of the valve stem to the stem tip, and a quantity of coolin medium partly filling the head end cham er.

In testimony whereof I hereto affix my signature.

. SAM D. HERON.

partly filling the head end chamber, and a I tip permanently applied at the end of the stem holding said means in place.

5. An exhaust valve for internal vcombuslll 

